Totem Dreamcatcher monitor is relatively inexpensive and has worked well in a bookshelf for me.(My better system is in my study and the secondary one in the living room) It seems to benefit from the bass boost as the port is is in the back. The bass is not very smooth though, but adequate in my opinion,(only when the speaker is placed in a bookshelf). The presentation is also very forward and extremely dynamic. I think this helps the sound not get buried in the surrounding shelf.
Budget bookshelf speakers FOR a bookshelf...
am looking for a set (under $600) of bookshelf speakers that will actually sound good in a bookshelf. not on top, but on a shelf with a shelf of books above and below them. max of 10" wide by 14" high. i like all kinds of music, from abba to metallica, the planets to rammstein, al dimeola to joe bonamassa. used of course is just fine :)